Jokes for Women
Jokes for Women is a pressure group active in Ankh-Morpork which is capable of bringing an even deeper scowl to the sunny countenance of Doctor Whiteface. Referenced in Making Money, this particular group of suffragettes campaigns for equality in humour, recognition of the idea that women can be every bit as funny as men, the right for equal opportunities in joke-telling, and, by inference, for the admission of women to the Fools' Guild as full members and licenced Clowns. (And allied trades).
They must be active enough, and nuisance enough, for Lord Vetinari to be aware of their presence and to casually mention them to Doctor Whiteface, possibly in order to watch his reaction. Whiteface is certainly aware they exist, and reiterates the official Fools' Guild position that women are simply not funny, and that he was making a very big exception to the normally absolute rule, that no woman may darken the doors of the Guild, by admitting Miss Drapes. But these are very exceptional circumstances.
Clearly a reference to the famous slogan of the suffragettes on roundworld [Votes for women]